Tailoring large magnetoresistance in Dirac semimetal SrIrO3 films.

Perovskite SrIrO₃ is a special Dirac material with fascinating effects due to its strong electron correlation and spin–orbit coupling. In this work, a large magnetoresistance (MR) was observed not only in epitaxial SrIrO₃ films but also in a SrIrO₃/PbZr_0.2Ti_0.8O₃ epitaxial heterostructure with a magnetic field applied perpendicular to the external electric field. The magnetoresistance of SrIrO₃ (10 nm) and SrIrO₃/PbZr_0.2Ti_0.8O₃ (10 nm/30 nm) reach values as large as 40% and 110% at 9 T and 5 K, respectively. We believe that the unusual magnetoresistance is from the Dirac/Weyl state. Especially, the SrIrO₃/PbZr_0.2Ti_0.8O₃ bilayer shows negative magnetoresistance with strong oscillations close to the angle positions, where the magnetic field is parallel to the electric field at 1.8 K, which arises from the chiral anomaly. Based on first-principle calculations and study, the polarization field of PbZr_0.2Ti_0.8O₃ can modulate the band structure of SrIrO₃, which can modify the MR of SrIrO₃. The SrIrO₃/PbZr_0.2Ti_0.8O₃ heterostructure accommodating both the ferroelectric property and the Dirac/Weyl state may open the avenue to manipulate the Dirac/Weyl properties via the electric polarization field. [ABSTRACT FROM AUTHOR]